The aircon pipes on my Range Rover are aluminium and I had one that had corroded and was starting to leak. I replaced it in the end but did consider making a replacement using 10mm copper microbore central heating pipe.

I once had a Pug 306, broken condenser when I bought it but I replaced that for a new one from a local radiator and condenser specialist for about £100 (Pug part over £300). Then I found it had the common Pug problem of corroded bottom aluminium pipe to the condenser. Apparently they corrode due electrolysis effect when wet where the alloy pipe attaches to the car body with only a thin rubber bush. Anyway, a new pipe from Pug would have been another £300 and would have meant having the dashboard out to fit it because it goes straight through the firewall to the AC evaporator... So I cut the rotted section of alloy pipe out leaving most of it in place but removing from the rot to where it connected to another section of alloy pipe (to the condenser). Got a hydraulics firm to make me a pipe up (about £10) that would properly attach to the other section of pipe and simply J clip (I used 3) around the cut-off end of pipe. AC worked fine and was working just as well when I sold the car 3 years later.

A job that would have cost £600 in bits and involve having the dashboard out only cost £110 and didn't involve having the dashboard out.

I did have the chat with the hydraulics specialist about pipe compatibility with the AC gas and they assured me it was OK. As far as I remember, the pipe used was just a rather flexible (to enable the J clips to work) but otherwise normal hydraulic pipe. JIC filler hose might even be compatible... Do your own checks before using though!

As LPG is a hydrocarbon and AC refrigerant is a hydrocarbon, I suspect that anything that is good enough for LPG will be good enough for AC. So why is it OK to use plastic coated copper as the feed line? You can, if you are absolutely sure you don't have any leaks (which could make it interesting) fill an older R12 system with Propane and it will work fine.

Gilbertd wrote:As LPG is a hydrocarbon and AC refrigerant is a hydrocarbon, I suspect that anything that is good enough for LPG will be good enough for AC. So why is it OK to use plastic coated copper as the feed line? You can, if you are absolutely sure you don't have any leaks (which could make it interesting) fill an older R12 system with Propane and it will work fine.

I had the same thoughts on HC compatible pipe at the time I fixed the Pug too, and it worked out well (no apparent issues with the hydraulic pipe running AC gas). It just occurred to me that alcohol is an HC but some pipes that we might expect to be OK carrying HCs are damaged by ethanol in petrol... So I checked Google and found alcohol isn't an HC strictly speaking because it contains OH (that'll be the reason for the different name and chemical class then).. Must be the OH that damages none compatible pipes, my chemistry lesson for today!

I can't see any issues with copper either, unless anyone knows of a problem with AC lube and copper.

Have known of propane being a substitute for R12 for a while but not long enough to have used it in my old 1983 mk2 Granada 2.8i GhiaX back in the day, bah! Used to travel 30 miles to a bloke who filled my AC up from a green/blue bottle and charged me £40 back in 1989. Propane would have cost pence and could have done it myself.. That car had 6 V belts, 2 of which drove the AC, but still when changing the plugs it was easier to remove the AC pump which obscured no1 spark plugs, a pain to work on. Went to an American car show just before I sorted my AC system on that car and hearing a group of Yank owners discussing AC I asked them if they knew where I might get my system charged.. None of the Yank owners believed a Euro car would have AC fitted, they laughed at me until they looked under my bonnet and saw AC was fitted (then sauntered off with tail between legs having offered no advise, ignorant ^**%)...

[quote]Poly alkylene glycol oils – or PAG – were the first oils developed for use with HFC refrigerants and are perfectly miscible with these products. However they are very hygroscopic. PAG oils are mainly used in copper-less car air conditioning systems using R-134a, because of their tendency to absorb water and their incompatibility with copper. Being perfectly miscible with ammonia , PAG oils were adopted in refrigeration systems using this refrigerant.[/quote]

LPGC wrote:I can't see any issues with copper either, unless anyone knows of a problem with AC lube and copper.

Talkingcars wrote:Poly alkylene glycol oils – or PAG – were the first oils developed for use with HFC refrigerants and are perfectly miscible with these products. However they are very hygroscopic. PAG oils are mainly used in copper-less car air conditioning systems using R-134a, because of their tendency to absorb water and their incompatibility with copper

I probably wouldn't risk copper, had an inkiln I'd heard about PAG issues with copper years ago, something pushed to the back of mind but interested in this subject so had a quick Google. Seems 'Early PAG oils' could be relevant as I just found this.. http://www.kembla.com/assets/Uploads/Te ... t-logo.pdf

Our Antipodean colonials are well into the use of propane as a refrigerant to replace the now unlawful r12a, but if you want to stay on the right side of the law any mobile recharger should have the newer r417a in his box of tricks to get you cool again. It's directly compatible with r12a and the lubricant doesn't gel like some do. Since most of the Kwik Fit and larger (Halfrauds) concerns don't always do an accurate leak test, these mobile guys often have newer and more sensitive equipment. You should find a good handful with just a quick google/Yell/yellow pages search and a few phone calls. Simples!